A Gymbag surprise is when your mother sends you a care package filled with extra clothes, deodorant, and other supplies. Upon receiving the package, you realize that she sent the items to you in one of her bags. You think nothing of it until, you have emptied all of YOUR belongings out, but the bag is still heavy.... You open up the side pouch to find your mom left her dildo and lube in the bag and sent it to you!!!!!
Tom can never look at his mother the same after she hit him with a gym bag surprise!
Sam doesn't know how he can ever thank his mom for the gym bag surprise.
Someone who is particularly smelly, and consists of a lot of unwanted personality traits. Someone who is a gym-bag is very irritating, and gets on everyone's last nerve.
A person who refuses to pay dues for a gym membership or sneaks into a gym for a workout without paying. An illegal gymagrant often convinces gym managers that they are going to "test out the gym" prior to signing up for an official membership where they have to pay.
Did you know that that guy has been working out for the last six months at the local gym and has never initiated a membership? He's such an illegal gymagrant!